I saw another thing on TV that took into count the water that you eat in vegetables, etc which brings down what you need to drink.
You can drink too much water. You can actually die from it if you drink too much. You would have to google that for the facts. Dilutes your organs too much.
I also saw a lady on TV who was addicted to water. She started on a diet and instead of eating she would drink water. It bloated her. She was huge and she said that if she was anywhere if you ask anyone for water they will give it to you, so she was so addicted she couldn't quit.